This invention relates to a chain and shaft drive for a balloon tired motorcycle and more particularly to an improved drive for such a motorcycle embodying a drive shaft in the final drive portion.
It has recently been proposed to equip motorcycles with large, low pressure balloon tires to adapt them for off the road use. The rear wheel and its mounted tire generally have a width that is at least equal and oftentimes greater than the width of the frame. This presents certain problems in connection with the drive of the rear wheel. For example, if the rear wheel is driven directly from the output shaft of the engine, then the final drive extends at a substantial width relative to the longitudinal center line of the motorcycle from the engine rearward. This provides a substantial increase in width in the area between the rider's legs and gives rise to an unnatural riding position.
In order to overcome these difficulties, it has been proposed to provide a two chain drive for the rear wheel such as shown in copending application Ser. No. 632,717, filed July 20, 1984 in the name of Nobuaki Shiraishi, entitled "Offroad Running Motorcycle" and assigned to the same assignee as this application. Although this type of arrangement has the advantages of maintaining a narrow width in the area between the rider's legs, it presents certain disadvantages. For example, when a two chain drive is employed, it is difficult to provide an adequate and yet simple mechanism for adjusting the tension on the individual chains. In addition, the final drive chain is of such a size that it can easily be contaminated during the off the road use, particularly when leaning the vehicle for turning in sandy territory or the like.
It is, therefore, a principal object of this invention to provide an improved drive mechanism for an off the road motorcycle.
It is a further object of this invention to provide an improved and compact drive arrangement for an off the road vehicle.
It is a still further object of this invention to provide an improved drive arrangement for an off the road vehicle wherein a shaft is used as the final drive.